Riving machine



Oct. 8, 1929. E. MILLER RIVING MACHINE Filed Aug. 27, 1928 IN VENTOR 624ml 9/07/11 A ronmw' Patented Get. 8, 1929 watt EDWARD MILLER, 0F ADRIAN, MICHIGAN, ASSIGNOR T0 EVANS AUTO LOADING COM- PANY, INQ, 0F DETROIT, MICHIGAN, A CORPORATION'OIE DELAWARE RIVING MACHINE Application filed August 27, 1928. Serial No. 302,210.

This invention relates to riving machines,;

the principal object being the provision of new and novel means permitting the ejection of the slabs from the hopper without liability of damage to the machine.

Another object is to provide a hopper construction for riving machines in which the hopper may move away from the cutter head when a slab attempts to be wedged between the cutterhead and the hopper.

A further object is to provide a hopper for a riving machine suitably guided for movement transversely to the plane of the knife and resiliently urged toward normal position adjacent the knife.

The above being among the objects of the present invention, the same consists in cartain features of construction and combination of parts to be hereinafter described with reference to the accompanying drawing, and then claimed, having the above and other objects in view.

In the accompanying drawing which represents a suitable embodiment of the present invention and in which like numerals refer to like parts throughout the several different views, i

Fig. 1 is a fragmentary more-or-less diagrammatic plan view of a rivingmachine.

Fig. 2 is a vertical sectional view taken on the line 22 of Fig. 1.

Fig. 3 is a vertical sectional view taken on line 83 of Fig. 1, illustrating the manner in which the hopper is secured to the side bars of the machine.

Fig. 4 is an enlarged fragmentary sectional,

view illustrating in detail the connection employed between the hopper and side bars of the machine.

As is commonly known, riving machines are employed for splitting off from a block of wood a thin sheet commonly known as veneer. In the conventional type of riving machine a reciprocatory cutter head is provided with a knife, and a suitably prepared block of wood is fed into the knife so that upon each reciprocation of the cutter head the knife splits a sheet of veneer from the block. Ordinarily the knife lies in a substantially horizontal plane and the cutter head is reciprocated in a horizontal plane, the block of wood or stock being fed vertically downwardly into the knife. WVhat is generally known as a-hopper is employed for guiding the'block of wood or stock into the knife, and this hopper may take various forms but usually comprises a rectangular frame in which the block is received and guided in its downward movement. The hopper extends downwardly into relatively close but spaced relationship with respect to the path of movement of the cutting. edge of the knife. r i

The blocks of wood employed as stock for the veneering are seldom of absolute rectangular shape in vertical section, with the result that as the successive strips of veneer are split off of the same, the block decreases in thickness until the unusable residue of the same, which is commonly known a the slab is left, which, because of the fact that the block is not absolutely rectangular as described, is invariably of wedge shape and one edge of the same is suificiently thin to pass between the lower edge of the hopper and the cutter head. When this thin edge of the slab lies on that side of the same more advanced in the direction of movement of the knife during the cutting stroke thereof, the knife on its cutting stroke engages the thickened end thereof'and attempts to force the slab between the cutter head and the lower edge of the hopper. This action tends to force the hopper upwardly, and as in conventional practice such hoppers are rigidly secured'to the frame of the machine, it often happens that the wedging action of the slab either breaks the hopper or breaks the securing means which hold it to. the frame and tears it from the machine. The vertical component of the wedging force sometimes approaches very high values due to the small angularity of the wedge surfaces and the force behind the cutter head, and it may be readily recognized that these forces sometimes assume such n proportions as to easily wreck the hopper.

The object of the present invention is to provide means for mountingthe hopper on the machinewhereby when such wedging effect of the slab between the cutter head and the hopper occurs the hopper may move away from the cutter head to permit the ejection of the slab beneath it without causing damage to the machine.

Referring to the drawings, represents the side bars of a riving machine between which the cutter head is suitably mounted for reciprocation. The cutter head may comprise a frame 11 having formed thereon a horizontally disposed table 12 and supports Cir 13 for a knifel, the knife 14 being secured to the supports 13 by means of bolts 15. The cutting edge 16 of the knife 14: lies substantially in vertical alignment with the adjacent edge of the table 12 and spaced an amount above it corresponding to the thickness of the veneer to be cut. Secured, as will hereinafter be described, to the side bars 10 and extending between them in overlying relationship with respect to the cutter head is a hopper comprising a frame 17. On that side of the hopper more advanced in direction of movement of the knife during the cutting stroke is secured a pair of spaced vertically extending guide members 18, the lower edges of whichextend into close but spaced relationship with respect to the path of travel of the cutting edge 16 of the knife. A pair of similar guiding members 19 are supported on the opposite side of the frame 17 from the members 18, and in opposed relationship with respect thereto by means of members 20 which are slidably secured to the upper face of the frame by straps 21. Bolts 22 and springs 23 cooperate with the members 20 to constantly urge the members 19 toward the members 18. This particular construction of the hopper shown is the subject of another patent application filed by me on even date herewith, and has no reference to the present invention other than illustrating a suitable hopper that may be provided in connection with the present invention, it being understood that any other type of hopper mechanism including the features of the present invention, may be equally well employed in its place.

In accordance with the present invention, the hopper, or more specifically the hopper frame, is secured to the side bars 10 in the following manner. The side bars; 10 are each provided at points thereon corresponding to the overlying portions 26 of the hopper frame 17 with vertically extending post members 27 secured rigidly in place by nuts 28. The ends 26 0f the hopper frame slidably engage the posts 27 which thereby act to guide the hopper frame for vertical movement. The posts 27 are each provided with an enlarged head 29, and a coil spring surrounding each post 27 is held under compres sion between the head 29 and the corresponding end 26 of the hopper frame. It will thus be apparent that the hopper frame 17 is maintained in its lower and normal operating position against the side rails 10 by the coil springs 30 as well as the weight of the hopper, and is maintained against movement in a horizontal plane by the posts 27.

In operation, the cutter head is caused to reciprocate back and forth by means of a drive rod such as 24 driven by suitable mechanism (not shown), and during such reciprocation a block of wood such as 25 is inserted between the members 18 and 19 and is fed downwardly against the table 12 by any suitable means such as manual pressure, that part of the block between the table and cutting edge 16 upon each reciprocation of the cutter head being split from the block and ejected between the cutting edge 16 and table 12 to a point below the machine. The block 25, during this vertical movement is resiliently clamped between the members 18 and 19 by the action of the springs 23. It may be noted that the springs 23 and members 19 are positioned on that side of the hopper opposite to that upon which the pressure of the knife in cutting acts. As the block 25 is reduced in thickness until only the slab remains, if the thin edge of the slab on the cutting stroke of the knife gets between the lower edges of the members 18 and the table 12 (which in conventional constructions might break the hopper as above described) in the present case the frame 17, members 18 and 19 and other'parts carried by the frame 17 will merely move upwardly on the posts 27 against the pressure of the springs 30 a sufficient amount to permit the slab to be ejected from beneath the hopper, and as soon as the slab is thus ejected the springs 30 will again move the hopper mechanism back to normal position without any interruption in the cutting operations. It will also be apparent that the same action will take place when a slab attempts to be wedged between the hopper and the knife on the back stroke of the cutting head whenever such a condition arises. This same action will also take place without the employment of the springs 30, and they may be dispensed with entirely where the weight of the hopper and its mechanism are sufficient to normally maintain the hopper in its lowermost position with reasonable accuracy, although it is usually desirable to employ the springs 30 to insure the hopper being held down in its normal position except when the slabs are being ejected beneath the hopper.

It will be apparent, of course, that the details of the construction of the hopper itself are immaterial to the practice of the present invention so long as it is suitably supported and guided for movement away from the plane of the knife and normally maintained in its normal operating position.

Formal changes may be made in the specific embodiment of the invention described without departing from the spirit or substance of the broad invention, the scope of which is commensurate with the appended claims.

What I claim is:

1. In a riving machine, in combination, a

horizontally recip'rocatory cutter head, a sta tionary support, posts on said support projecting vertically therefrom, and a hopper frame slidably engaging said supports and normally urged toward said cutter head.

2. In a riving machine, in combination, a horizontally reciprocatory cutter head, a stationary support, and a hopper frame carried by said support in overlying relationship with respect to said cutter head and guided for vertical movement relative thereto, said hopper frame normally seating against said support.

3. In a riving machine, in combination, a stationary support, a hopper mounted on said support and guided for movement relative thereto, and spring means constantly urging said hopper toward a fixed position relative to said support.

4:. In a riving machine, in combination, a reciprocatory cutter head, a stationary support, a hopper carried by said support for movement transversely to the path of movement of said cutter head, and spring means constantly urging said hopper toward said cutter head. 7

5. In a riving machine, in combination, a reciprocatory cutter head, a stationary support, a hopper carried by said support and movable bodily toward and away from said cutter head, and spring means constantly urging said hopper toward said cutter head.

6. In a riving machine, in combination, a

statonary support, posts projecting from said support, a hopper frame ,slidably engaging said posts, and spring means constantly urging said frame in one direction on said posts.

EDWARD MILLER. 

